The use of <H> is from Klingon and Arabic, <3> /ʕ/ is from Kabyle ɛ and Arabic, <N> is sometimes used for /ŋ/ when romanizing languages from India. Regarding /ʃ/ <S>... do we allow /sh/ to happen at all? If we don't we could simply use <sh>. I can type ŝ or ś or š easily, but I think of our mates on Windows 10...

Alternatively, /ʃ ħ ʕ ŋ/ <S H 3 N> can be written with the IPA symbols. We should agree on only using one set or the other when making the Annie dictionary though.

vowels:

ɪ iː ʊ uː
ɛ eː ɔ oː
æː ɑ ɑː

-ɛ comes from a merger of older short /ɛ/ and /æ/, maybe this has morphological consequences

To Kabyle-ize this I'll just take out a bunch of vowels. What do you think of cutting the length distinction down to the Persian system?

The phonemes, with suggested romanization:

/i e æ ɑ o u/ <i e æ a o u>

We could kind of keep your idea about /ɛ/ by saying /æ/ is always unchecked (can only appear in open syllables), and if it gets morphologically checked then it becomes /e/ <e>. So if we have a singular-plural paradigm like sg. */kæbi/, pl. */kæbnu/, then we get /kæbi/ and /kebnu/.